[Effectiveness and adverse effects of a single daily dose of gentamicin versus twice daily administration].

The efficacy and toxicity of a single versus double gentamicin dose were compared. Fifty-four ill patients with infection susceptible to gentamicin in Department of Internal Medicine, University Hospital Rebro, Zagreb, were included in this study. The following criteria excluded patients from the study: serious renal failure (creatinine > 250 mumol/l), hearing impairment, condition and immunodeficiency. Patients were randomised to receive either gentamicin 4 mg/kg by infusion over a 30 minute period once daily, a single-dose group (SG) (N = 25), or gentamicin 2 mg/kg intravenously twice daily, a double-dose group (DG) (N = 29). Almost all patients in a single-dose group achieved peak therapeutic concentrations, while trough gentamicin concentrations were below the recommended. In a double-dose group, only 70.5% of the patients obtained peak concentrations, and 7.5% of the patients had inadequately high trough gentamicin concentrations. In a single-dose group, there were no changes in serum creatinine values, while in a double-dose group there was a significant increase in serum creatinine concentration and a decrease in serum creatinine clearance. Risk factors for gentamicin nephrotoxicity were: through gentamicin concentration, older age and initial abnormal renal function. Ototoxic reaction developed in 35% of the patients on a single gentamicin dose and in 44.8% of the patients on a double dose (P > 0.05), and a lesion was more diffuse in this group. Risk factors for gentamicin ototoxicity were: through gentamicin concentration, duration of therapy, older age and abnormal renal function. Therapeutic effect was observed in 96% of the patients in SG and in 86.2% of the patients in DG (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)